The rotor hub of a wind turbine contains various systems, such as, for example, the blade pitch angle controller (pitch controller) for the rotor blades which are controlled by a central management system of the wind turbine. In order to control them, but also to transmit signals from the blade pitch angle controller (pitch controller) to the management system, a data transmitter is required between the rotating rotor hub and the stationary nacelle.
In wind turbines, slip ring transmitters have proved themselves when transmitting electrical signals and electrical power between a rotating rotor hub and a fixed nacelle. For the transmission of the electrical signals, recourse can be had to an electrical, optical, inductive or capacitive transmission path.
For the transmission of liquid or gaseous substances, rotary media leadthroughs via which, for example, water, oils or gases can be transmitted have proved themselves.
The electrical blade pitch angle control (pitch control) in wind turbines is often achieved by a slip ring system which, as a transmission device, transmits electrical energy and signals from the fixed electrical system of the nacelle of the wind turbine into the pitch system, which rotates with the rotor of the wind turbine, in the rotor hub assembly. For this purpose, a fixed line pipe (also pitch pipe) which receives and protects the electrical lines routed from the fixed nacelle into the rotating rotor hub extends within a core bore in the rotor shaft. The line pipe is customarily mounted, on the one hand, behind the gearbox and, on the other hand, on the rotor shaft flange, which is provided to fasten the rotor shaft to the rotor hub, by a second bearing arranged there. In this way, the rotor shaft rotates about the line pipe.
U.S. Pat. No. 8,313,297 discloses a rotor shaft for a wind turbine, wherein the rotor shaft is at least partially hollow. Arranged in the rotating rotor shaft are a line pipe which receives electrical lines and a transmission device which produces an electrical connection between a fixed nacelle and a rotating rotor of the wind turbine. The line pipe is supported in the rotor shaft via two bearings, wherein one bearing is arranged on the housing of the transmission device in the region of the end of the rotor shaft that faces the rotor hub and a second bearing is arranged in the region of the end of the rotor shaft that faces away from the rotor hub.